The leader of the coalition governing Kurdish-held areas of Syria called on the international community to impose a no-fly zone over the northwestern enclave of Afrin to stop Turkish air strikes he said were killing innocent civilians.

Turkey launched an air and ground assault on Afrin two weeks ago, pledging to destroy the People’s Protections Units (YPG) it says are linked to separatists Kurds fighting the Turkish state for more than 30 years.

“We firmly believe that imposing a no-fly zone over Afrin would be useful to protect innocent civilians and put an end to Turkish aggression,” wrote Aldar Khalil, the co-chair of the Democratic Society Movement, on the U.S.-based DefenseOne website .

Cooler heads are needed in relations between the United States and Turkey, as breaking ties altogether would have “sustained consequences” for both sides, saidÖzgür Ünlühisarcıklı, head of the German Marshall Fund’s Ankara office.

It would be very difficult for Washington or Ankara to find a substitute should differences over matters such as Turkey’s invasion of northern Syria become irreconcilable, he said.

“The United States does not have any other partner in Turkey’s neighbourhood with the same capacity — and the PYD (the Kurdish militant group that controls territory in northern Syria) can certainly not grow into one,” Ünlühisarcıklı said.

Turkey has abandoned its Western-dominated approach to Middle East strategy and is actively seeking to draw up “new maps” for the region, backed by relations with Qatar and Russia, Shehab Al-Makahleh wrote in Al Arabiya.

Turkey is partnering with Russia and Qatar because it doesn’t have the financial capabilities to expand its horizons alone due to a decline in the economy, said Al-Makahleh, who is director of the Geostrategic Media Center .

Turkey sent a convoy of troops into the Syrian province of Idlib on Monday, to establish a new observation point in accordance with a peace deal agreed with Russia and Iran, Turkish state-run Anadolu Agency said .

Turkish authorities detained 449 people for "making propaganda of terrorism" via social media posts over Turkey's incursion into Syria's Afrin, the interior ministry said in a statement cited by Anadolu Agency.

Turkish elections, due next year, may mean President Recep Tayyip Erdoğan won’t be interested in cooperating with the United States in Syria and an armed confrontation could be inevitable, Thomas Seibert wrote for the Arab Weekly, citing a former U.S. envoy to Turkey.

The longstanding alliance between the United States and Turkey could collapse under the strain of events in Syria, especially if the Turks push on to Manbij, where U.S. troops are stationed, Seibert said.

“A serious rift between Turkey and the United States could plunge NATO into crisis and push Ankara further away from the West. It also allows for increased Russian influence in the region,” Seibert quoted W. Robert Pearson, ambassador to Turkey between 2000 and 2003, as saying.

Two more Turkish soldiers were killed Sunday in Turkey's offensive against Kurdish militia inside Syria, the army said, bringing to 16 the number killed so far in the incursion.

Five Turkish soldiers were also wounded in operations inside Syria on Sunday, the army said in a statement quoted by the state-run news agency Anadolu. It did not give further details on the circumstances of the deaths and injuries.

The army also said 12 members of the Syrian Kurdish militia were killed on Sunday, and 947 since the incursion started on Jan. 20.